adk-java

Why we included this project

Java teams that want more control than a Python-first agent framework usually offers will find this Google-maintained toolkit worth a look. Agent behavior, sub-task orchestration, and tool access are all defined directly in Java code, which keeps the whole thing testable and versionable instead of a black box. It ships with pre-built tools like a Google Search tool, accepts custom functions and OpenAPI specs, and lets you compose specialized agents into hierarchies for multi-agent setups. If you already run on Google Cloud, the integration is a clear plus, and A2A protocol support lets its agents talk to remote agents. A bundled development UI handles testing and debugging, so it can carry a project from early prototyping into deployment.